1. Field of the Invention
The present invention relates to a variable-geometry stablizing foot which can be mounted in particular on earth-moving vehicles.
2. Prior Art
As is known, stabilizing feet are mounted on special vehicles subject to intense destabilizing thrusting forces, in order to provide support bases which are much more stable than those provided by wheels alone.
At present, in accordance with the known art, substantially two types of stabilizing feet are used. A first type of stabilizing foot is mounted vertically on the chassis of said vehicles, being generally arranged in pairs on the rear part of the vehicles themselves. This type of stabilizing foot, already known in the art, consists of a support sleeve, integral with the vehicle body, and an extendable arm slidably mounted inside the support sleeve and having a bottom end provided with a support foot for ensuring a grip on the ground. By means of a (hydraulic) actuating system, the extendable arm is moved so as to extend from the support sleeve towards the ground until it comes into contact therewith by means of its support foot. Generally this type of stabilizer is provided with a hydraulic jack having a support foot connected to the free end of the internal stem. In practice, this type of stabilizer has proved to have drawbacks.
A first drawback arises from the fact that the earth-moving vehicles have the excavator arm mounted on a carriage movable horizontally on the rear side of the vehicles themselves. In this way, the position of the stabilizing feet, designed in accordance with the known art described, constitutes an obstacle for the carriage movement (which is in fact restricted horizontally), preventing the possibility of optimum operation of the excavator arms.
Moreover, since this type of stabilizing foot is able to perform only a vertical movement, it does not allow the support base of the vehicles to be modified in accordance with the operating needs which may arise.
In order to overcome these drawbacks, a second type of stabilizing foot (extending in an inclined manner) has thus become widespread, said foot being connected to the vehicle chassis by means of a hinge able to allow orientation thereof in accordance with operational requirements. In a similar manner to the first type, this stabilizing foot consists of an external support sleeve and an extendable arm sliding inside it. The extendable arm has passing through it along its longitudinal extension a series of through-holes able to match a selector hole formed on the support sleeve. By means of a fixing pin, which can be movably inserted into the selector hole and fitting into one of the holes of the extendable arm, it is possible to fix the support sleeve and the extendable arm with respect to one another. Operationally speaking, it is therefore possible to remove the pin from the selector hole, displace the extendable arm inside the support sleeve and re-insert the pin into a new hole of the extendable arm. Once the length of the stabilizing foot has been chosen by means of insertion of the pin into the selected hole, it is possible to operate the stabilizing foot hydraulically, causing it to rotate on the hinge until the support foot comes into contact with the ground. The use of stabilizing feet of this type which can be varied lengthwise makes it possible to modify the support base of the vehicle. This second type of stabilizing foot, however, during use has also proved to have some disadvantages.
First of all, such stabilizing feet transmit a notable thrusting force in an oblique direction on the ground, causing the deformation thereof in the zone where the foot rests. Since, in most cases, the ground consists of the road surface, a costly operation involving reconstruction of the damaged parts of the road is often necessary.
Another disadvantage arises from the fact that, in order to be able to vary the support base formed by the stabilizing feet, it is necessary to displace the position of the extendable arm inside the support sleeve by means of a manual or hydraulic operation, the first being difficult and awkward and the second costly.
The drawback of this second type of stabilizing foot consisting in damage to the road surface does not arise for the stabilizing feet of the first type which, acting in an exclusively vertical direction, do not damage the road surface. On the other hand, since the stabilizing feet of the second type are mounted below the chassis of the vehicle at the rear thereof, they do not obstruct at all sliding of the carriage on which the excavator arm is mounted.